In a process referred to as paper web finishing, a paper web is converted into a product. Paper web finishing can vary from one product to another. For example, some products may be printed and folded and others may simply be printed. While some products are manufactured in quantities that justify a dedicated assembly line, many products are not. As a result, the assembly line associated with a particular paper web-finishing requirement must be configured when needed.
Traditionally, the assembly line for paper web finishing has been characterized by relatively inflexible assembly line design. When a product was ordered, the processing requirements and the associated process equipment would be identified and a fixed assembly line would be designed and arranged.
A significant challenge in creating an assembly line from these disparate pieces of process equipment is assuring that the speed of the paper web through any given piece of process equipment is the speed required for that process. As a result, the assembly line had to include storage mechanisms to assure that the paper web could be processed continuously. The relatively inflexible design and the integration difficulties of the process equipment made paper web finishing expensive.
In order to reduce the costs associated with assembly line setup, individual process modules were developed. These individual process modules are standalone units performing a dedicated process. The individual modules are on wheels and can be rolled into position and held in position to create an assembly line. The use of positional individual modules increased productivity and thus lowered cost. Each module, however, is by design a standalone machine. As a result, each is optimized for its process and each has a drive system for moving the paper web through the module designed in isolation from the drive systems of other individual process modules. Thus when the modules were configured into an assembly line, differing drive speeds still had to be considered.
Eventually, the drive units of each process module were integrated. In essence, a master drive was created, mechanically or electrically, and the individual drive units were considered slaves to the master drive unit. This however, added considerable control complexity to the assembly line.
Based on the foregoing, it is the general object of the present invention to overcome or improve upon the problems and drawbacks of the prior art.